Stark divisions have emerged between the two parties, with several Fine Gael backbenchers coming out in defence of the €100m state subsidy to fee-paying schools in their middle-class constituencies.

And Fine Gael parliamentary party chairman Charlie Flanagan went a step further by directly criticising Labour Junior Minister Alan Kelly for his comments about the need to cut state support for private schools.

"The public debate on this issue has been shrouded in claims of elitism and privilege and false perception," said Mr Flanagan.

Choice

He said this was "exemplified by Mr Kelly's remarks that parents who make a choice and sacrifice to send their children to fee paying schools can afford to pay more and more, so the State can pay less and less".

Agriculture Minister Simon Coveney was also implicitly critical of Mr Kelly for commenting on fee-paying schools.

Mr Coveney said that Fine Gael backbenchers were "responding to comments that came out of left field on this issue".

"If we're going to have a discussion on this issue it should be around the Cabinet table, rather than over the airwaves," said the Fine Gael minister.

Mr Kelly had made it clear over the weekend that he supported the withdrawal of state funding for teachers' salaries in private schools. He said the funding was a "luxury rather than a necessity" and that his colleagues in the Labour party felt very similar.

Meanwhile, Education Minister Ruairi Quinn said his department's audit into the earnings of fee-paying schools -- estimated at €120m a year -- was nearing completion.